In addition, Ghali (1976) evaluated the contribution of Hawaiiûs tourism to the rate and stability of economic growth using an ordinary least squares (OLS) method. The study found that not only was the variability of growth larger with tourism growth, but also the coefficient of variation was larger in the absence of tourism growth. Therefore, it appeared that the growth of tourism contributed to the instability of growth in addition to its contribution to growth. The author concluded that it might be correctly argued that in discussion of growth, the relevant variable is the rate of growth of per capita income and the results will still be valid if population growth can be regarded as exogenous. Balaguer and Cantavella-Jorda (2002) examined the role of tourismûs long-run economic development in Spain.